Subject invention relates to a novel gas-liquid contact unit, which can be employed in conjunction with a portable detector device for testing the atmospheric environment for the presence of toxic substances. The detector device includes a gas-liquid contact unit, hereinafter referred to briefly as a bubbler unit, connected by tubing to a small, battery powered vacuum pump, and a harness to permit carrying the device by the person. The bubbler unit is small enough to fit into the shirt pocket of the wearer and contains a suitable liquid, eg. an acidic solution, for absorbing one or more toxic or hazardous substances contained in the environmental atmosphere. The pump draws the atmosphere, to which the wearer is exposed, through the bubbler, which monitors the presence and concentration of the hazardous substances in the atmosphere. Thus, the detector device can be worn by the person in hazardous areas, such as chemical plants and laboratories, where it is desired to monitor the presence of one or more toxic substances present in the atmosphere. In operation the vacuum pump draws the atmosphere through the bubbler at a known constant rate. After a suitable period the absorber liquid is removed and analyzed. The concentration of a particular toxic material in the atmosphere breathed by the person can then be calculated from the amount of the toxic material found by analysis in the absorber liquid and the volume of atmosphere introduced.
In the past, a serious deficiency of such portable detector devices has resided in the lack of a satisfactory bubbler unit. In particular, the bubbler unit, when tipped or severely jostled or shaken, allowed the absorber liquid to spill or leak from the unit. Since the bubbler unit is under constant vacuum, the spilled liquid was drawn into the vacuum pump and lost, thereby nullifying the analytical results. Moreover, the vacuum pump would suffer serious damage from the action of the corrosive acidic absorber liquid thus introduced.